No abstract

No abstract

In the present paper, we reported the fabrication of a highly hydrophilic nanometer-scale modified surface on a poly(ether ether ketone) (PEEK) substrate by photoinduced graft polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) in the absence of photoinitiators. Photoirradiation results in the generation of semibenzopinacol-containing radicals of benzophenone units in the PEEK molecular structure, which acts as a photoinitiator during graft polymerization. The poly(MPC)-grafted PEEK surface fabricated by a novel and simple polymerization system exhibited unique characteristics such as high wettability and high antiprotein adsorption, which makes it highly suitable for medical applications.

No abstract

We developed a cross-linked polyethylene (CLPE) modified with a phospholipid polymer in order to address the serious problem of osteolysis caused by wear particles derived from the polyethylene components of artificial hip joints. Our goal of preventing aseptic loosening could be achieved by avoiding any formation of CLPE wear particles or suppressing the activation of cell systems by the wear particles. We investigated the surface and wear resistance properties of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer grafted onto the surface of CLPE (CLPE-g-MPC). The relative density of MPC polymer chains was determined by the P-O group index. Generally, polymerization times correspond to the number of polymer chains in radical polymerization. After 3.0 x 10(6) cycles in a hip joint simulator test, the steady wear rates of the untreated CLPE and CLPE-g-MPC cups with a low P-O group index were as high as 4 mg/10(6) cycles; those of the CLPE-g-MPC cups with high P-O group indexes, that is, 0.46 and 0.48, markedly decreased to -1.12 and 0.16 mg/10(6) cycles, respectively. Therefore, the grafting of an MPC polymer with high density would be essential in order to maintain the long-term wear resistance of CLPE-g-MPC as an orthopedic bearing material.